[plt-scheme] Re: Word permutations - with a slight twist

Noel Welsh wrote:


> I suggest you start by writing the procedure that, given a
> list of symbols, generates all the one-step permutations.
>
> E.g. Given
>
>   '(aa bb)
>
> generate
>
>   '(aaaa bbaa aabb bbbb)
>

Just a little more help please.

What would the one-step permutations be for my case where I am given

'(aa b)

but have to generate 4 letter words. Thats a bit more complex than your
example and I wish to solidify what you mean by a 1 step permutation.